Safety means for elevators



@a zto 1, T1935 B. J. WINNER SAFETY MEAN FOR ELEVATORS Filed Oct. 13, 1953 DAN GER Inl/en'ggr Patented Oct. 1, 1935 UNITED STATES PATENT OFFIQE SAFETY MEANS FOR ELEVATORS Benjamin J. Winner, Chicago, Ill.

Application October 13, 1933, Serial No. 693,449

Claims.

My invention relates to means which may be readily installed intermediate of the power supply and the elevator cab controlling motors and which is adapted to interrupt the power supply 5 to the elevator controlling motor.

The invention has for its object the provision of means operable from the top and the bottom of the cab of the elevator when repairs or adjustments on the elevator are to be made whereby the inadvertent starting or running of the elevator will be impossible.

My invention is particularly adapted for controlling the operation of electrically operated elevators and involves means preferably arranged both on top of the cab and on the bottom to permit the service or repair man to control the circuit while engaged in making repairs either on top or below the cab.

The purpose of my invention is to prevent the accidents that have occurred to men while working on elevators because the elevators were inadvertently started up or down by an uninformed operator or other workman up in the pent house above the elevator-shaft. Many accidents and deaths have resulted in the past because the elevator undergoing inspection or repair may be and often is made to move upwardly or downwarolly through manual operation of the magnet control switches situated on the control boards in the pent house or machine room, while the men are working either on top or below the elevator.

With the elevator system equipped with my invention, it will be impossible to move the elevator after my improved means has been actuated by the workman positioned either above or below the elevator-cab, as will more readily appear from a detailed description of the embodiment shown in the accompanying drawing, wherein the figure diagrammatically illustrates an electric circuit and elevator cab provided with my improved means.

While the following is a detailed description of the preferred embodiment of my invention, it is to be understood that I do not intend to limit myself to the specific form disclosed, but intend to cover all modifications and alternative constructions coming within the spirit and scope of the invention as expressed in the appended claims.

As the circuit for operating the elevator is controllable by an operator in the elevator-cab, as well as by a workman in the pent house above the elevator-shaft, my invention contemplates opening the operating circuit by the workman or repair m'an through the opening of a small and properly housed switch merely accessible to the workman on top or beneath the elevator-cab.

In the drawing, it represents a manually operated switch for controlling the current from the 5 supply lines for operating the elevator; the drawing merely illustrating a single elevator circuit; similar circuit and elements being employed for each elevator-cab. While my improved means has been shown in connection with a widely used 10 two wire direct current system, with slight modifications, the improvment will work equally as well on a three phase, three wire alternating current system.

My improved m'eans involves a pair of suitable 15 and easily operated switches of the type known as three-way switches; one located on top of the elevator-cab II as generally indicated at E2, while the other is located on the bottom of the elevator-cab as indicated at 13; both switches 20 being preferably located or enclosed in suitable boxes as shown which are each provided with a small bulls-eye while the switch within the box involves a socket and lamp as at it for providing a light signal when the switch has been operated 25 or pulled outwardly from its normal position.

The usual controller mechanism in the elevator-cab H is generally indicated at I5; while the key controlled or baby switch, controlled by the operator through insertion of his key when 30 assuming control of the elevator, is indicated at 6. This switch I6 is shown open in the drawing and therefore prevents operation of the usual well known elevator motor and motor control switches, which are schematically indicated at IT. The 35 key operated switch It controls flow of current to the magnet switch indicated at it and which, like switch IE5, is also open. If the operator fails to close switch H3, magnet switch it will remain open and no current will flow to the motor 40 and motor control switches at ll and hence operation of the elevator is impossible. As soon as switch H3 is closed, movement by the operator of the controller lever in the cab, permits the elevator-cab to move up or down according to 45 the direction of movement of the control lever. The plunger I9 of magnet switch l8 carries contacts 20, 29 which are adapted to make contact with the contacts 2|, 2! and contacts 22, 22, thereby closing the circuit for the motor and 50 control switches generally indicated at H.

The supply lines 23, 23 instead of leading directly to the contacts 2|, 2| of magnet switch MS, as is the case in most circuits as heretofore employed, are connected to contacts 24, 24 because 55 I interpose my safety means operatively between the current supply and the magnet switch I8 which controls current flow to the motors.

Associated with contacts 24 are contacts 25, 25, and these contacts are adapted to be electrically connected through contacts 26, 26, which are insulatedly mounted on the plunger 21 of the electro-magnet 28. The upper end of the plunger 21 is shown provided with a coil spring 29, which normally maintains the plunger 21 in raised position with contacts 26, 26 in contact with points 24, 24 and 25, 25, thus supplying current by means of wires 30, 30, to contacts 2 I, 2 I, of magnet switch I8 and one of the contact points 24 is also connected with a lead line 3| which extends to the operators key controlled switch I6; while the other contact 24 has lead line 32 which connects with one point or contact in the workman control switches I2 and I3.

These switches I2 and I 3, it will be understood, are of the three-way type so that when these switches, are in normal closed condition, the circuit through wire 33 to magnet I8 is completed. On the other hand, if a workman pulls either safety switch I 2 or I3, or both, out of normal main circuit closing position as indicated at I2-(while switch I3 is shown closcd)--the current to magnet switch I8 will be disrupted causing the contact carrying plunger I9 to drop to open position indicated and thereby discontinue current flow to the motor.

The plunger 21, below the coil 28, is provided with a pair of contact forming elements 34, 34, insulatedly secured to the plunger and which are adapted to close circuits through the pairs of con tacts 35, 36.

The lower end of plunger 21 is shown provided with a small bevelled lip adapted to effect holding relation as indicated at 31, with the bevelled end of the plunger of the latching magnet v33 which is electrically connected with one point of the contacts 36 and with the lead line 39 which leads from the elevator cab switch IE to the magnet switch I8 the end of the plunger of magnet 38 and the side of the lip on plunger 21 are bevelled to permit the latter to force the former against the action of the spring 38.

One of the points of contacts 35 is shown connected with lead line 3 I, while the other point of contacts 35 is shown connected with lead line 33 which has connection with the lamp sockets I4 in the workman or safety switches I2 and I3.

As previously stated, one of the points of contacts 36 is connected with lock-magnet 38, while the other of said points is connected with an intermediate contact point of the three-way switches in both boxes I2 and I3, by means of wire 40.

When switch I0 is moved to circuit closing position current will flow by wires 23, 23 to contacts 24, 24, through wire 3|, operators key switch I6, wire 38 to magnet switch I8, wire 4I connected with wire 40 through the normally closed contacts of safety switches I2 and I3, wire 32 back to one of the contacts 24. Current passing through the magnet coil of switch I8 causes the plunger I9 to be drawn upwardly, bringing its contacts 20, 28 into contact with contacts 2|, 22 and thereby bringing themotor and motor control switches into the circuit, permitting operation of the elevator.

In the event of inspection or repair being necessary, the workman operates or pulls out the switch lever' 42 of safety switch assembly 01' box I2, if the repair is on top or above the elevator; or operates or pulls out switch lever 43 of safety .to break contacts 45, 45;

switch assembly or box I3 if the repair is beneath the elevator. In the drawing, the switch lever 42 of safety switch I2 is shown pulled or opened, thus disrupting the current flow through the coil of magnet switch I8, causing this switch to open as shown and hence breaking the circuit for the motor and motor control switch assembly at I1, preventing operation of the elevator.

When the switch lever 42 is fully pulled out and in contact with the contacts 44, 44, as shown, it closes the circuit of the coil of electro-rnagnet 28, causing the upper magnetic portion of plunger 21 to be drawn down against the action of spring 29, and inducing the lower end to pass the end of the spring controlled locking plunger of magnet 38, thereby locking plunger 21 in the lowered position shown in the drawing. When the plunger 21 is in this lowered position, the contacts carried by the lower end of the plunger will be in contact with contacts 35, 33, thereby providing current for the lamp I4 of safety switch assembly I2; the lighted bulb indicating to the workman on top of the elevator-cab I I that the safety device in the machine room has locked itself open and cut off all power feed going to the control board of the elevator.

At the same time the plunger 21 at its upper end will make contact at 45, 45, which will light up the bulb in the Danger sign shown at 16 which is located in the machine room and whichwillindicate to others in the room that a workman is work ing on that elevator.

When the workman has completed the repairs and after leaving the elevator, he pushes lever 43 of safety switch I2 completely inward, thereby opening the circuit of coil magnet 28 and subj ecting the plunger 21 to the upward force of spring 29. In view of the latching relation between plunger 21 and the plunger of magnet 38, plunger 21 cannot move upwardly. When safety switch I2 is pushed in completely, it partially closes the circuit of coil I8; the circuit of this coil not being completely closed until the safety switch it also is pushed in to reset or normal position and the operators key switch I6 (which the operator is also supposed to have opened) is also closed.

Even though the workman or safety switches I2 and I3 are closed, the elevator cannot be moved by manual operation of any switch in the machine room until the operator in the elevator has closed the switch I6. Closing this switch then causes current to pass through the coil of magnet switch I8, inducing plunger I9 to rise and close contacts 2I and 22 through contacts 20, 28, and also allows current to pass through the coil of latching magnet coil 38 through the contact 34, 38, causing the plunger of latch coil 38 to retract from looking relation with plunger 21, which permits spring 29 to force plunger 21 into position to again close contacts 24-2528.

This upward movement of plunger 21 causes it 34-35 and 34-36. Breaking contact at 45, 45 cuts the current for the danger bulb at 46, located in the machine room; while at 34-35 it shuts off current to the lamps I4 of the safety switch boxes I2 and i 3; and at 34-46 it breaks the circuit of the latching magnet coil 38, leaving the circuits in the original, normal working condition.

In the exemplification, I show protecting fuses at 41, 41 and 48, 48; fuses 41, 41, being employed by me to protect my safety mechanism in the event of an overload or short; these fuses 41,

41 being preferably employed in addition to the fuses 48, 48-, which are generally employed in the circuit.

As is apparent from the'foregoing description, when the workman pulls out either switch l2 or it, two operations are performed; first, it breaks or opens the circuit of the usual magnet switch i8 generally located on thecontrol board in the machine room, thus making it impossible for an operator in the elevator to operate the latter; and, secondly, the circuit, through the coil 28 of my improved safety means, is closed, energizing this coil and causing the contact carrying plunger 2'! to be moved from normal position to a point where it will be engaged by the locking means. It will be understood, of course, that my improved safety means is properly mounted in an enclosure or metallic box located in the machine room and normally not accessible.

My improved means or safety device is comparatively simple in installation and operation, being illustrated in conjunction with a two wire direct current system more or less universally used, wherein the power lines or leads 23 are generally lead to the contacts 2! of the magnet switch it, wh reas with my safety device interposed the power or current supply'lines 23 are shown leading to the contacts points 24, 24 of my safety means.

With my improved safety means accidental or unauthorized operation of the elevator through manual operation of the usual magnet control switches at l8l l, (which are usually situated on control boards in the pent house or machine room) will be impossible. With the mechanisms and switches generally employed in the elevator circuits, the safety of a repair man depends entirely upon no one tampering with the magnet control switches referred to, even though the operators switch it, is open. Many accidents and deaths have occurred in the manner mentioned. With my device, however, the operation of the elevator is entirely in the control of the repair man through operation of either switch H or I 3, whereby the usual magnet control switch at l8-l9 is not only opened but the circuit of this switch is disrupted by the operation of plunger 21, which is automatically locked in this position, thus making accidental or unauthorized operation of the usual magnet control switch I8 l8 impossible.

What I claim is:

1. Safety means for elevators comprising, in combination with the electric current supply lines, the elevator motor, the motor control switch, circuit closing switch in the elevator cab and the magnet switch interposed between said circuit closing switch and the elevator motor; means whereby current fiow to the motor and motor control switch may be discontinued, said means being electrically interposed between the supply lines and the magnet switch and comprising an electromagnet, a contact carrying plunger adapted to be moved into two positions, one of said positions normally closes the main circuit magnet switch, while the other position of said plunger is assumed when the electro-magnet is energized and the circuit of said first mentioned magnet switch thereby opened, and manually operated auxiliary switches carried by the elevator-cab whereby current to said second mentioned electro-magnet is supplied and said plunger moved into main circuit breaking position.

2. Safety means of the character described adapted to be electrically disposed intermediate of the current supply lines and the elevator motor switch and controls, comprising a magnet coil in a normally open circuit; a plunger controlled by the coil and normally adapted to close the main circuit or" the elevator motor switch and controls when in one position and also adapted to move to a second position when said coil is energized and thereby openfthe motor switch circuit and close a secondary signal circuit and manually operated switches arranged intermediate of said main circuit and the normally open circuit of said magnet coil whereby the normally open circuit is closed, the magnet coil energized and the plunger moved from its first mentioned normal position and the main circuit thereby opened.

3. Safety means of the character described adapted to be electrically interposed between the current supply and the main magnet coil switch in the elevator motor circuit and comprising a spring controlled contact carrying plunger for normally maintaining the circuit of the magnet coil switch when in one position and to close a secondary signal circuit and partially establish a locking means releasing circuit when moved from normal position into a second position; an electro-magnet coil associated with the plunger; automatic means whereby the plunger is locked in its secondary circuit closing position; and manually operated switches mounted on the elevator and independent of the usual elevator operating controls whereby the second mentioned electro-magnet coil is energized when said switches are closed, said plunger moved to its second position where the elevator operating current supply is disrupted and the plunger moved into engagement with said automatic locking means.

4. Safety means for elevators of the character described, adapted to be disposed intermediate of the current supply and the elevator motor switch and controls and comprising a manually operated auxiliary switch carried on the elevator and interposed between the current supply lines and the elevator motor switch, a contact carrying element normally adapted when in one position to close the main circuit of said motor switch and when in a second position to establish a signal circuit and to prepare a locking means circuit; an electro-magnet coil interposed between the main circuit and said auxiliary switch and adapted to move said element from its normal position into the second or signal circuit making position; and locking means electrically disposed between the motor switch and a contact point of the second position of said contact carrying element.

5. Safety means of the character described adapted to be electrically interposed in the main operating circuit intermediate of the current supply and the elevator motor switch and controls and comprising the combination of a spring controlled contact carrying plunger adapted to close the circuit of the motor switch when in one position and to open said motor switch circuit and to close a secondary signal providing circuit and partially completing a plunger locking means circuit when moved against the action of the spring into a second position; an electro-magnet coil interposed in the main circuit in advance of the motor switch and adapted when energized to move said plunger against the action of its spring and thereby open the main elevator motor switch operating circuit; a locking member adapted to automatically lock said plunger in its main circuit opening or second position; an electro-magnet coil arranged in said locking means circuit and adapted when energized to move said locking member out of plunger locking position; and a manually operated auxiliary switch arranged on the elevator beyond the control of the operator cab electrically intermediate of the main circuit and said first mentioned coil whereby current to said first mentioned coil is provided when the switch is moved out of its first or normal position, said plunger thereby moved against the action of its spring and the elevator motor switch circuit disrupted, the signal providing circuit closed and said plunger locking means circuit partially completed and said second coil of said locking means circuit being energized when said auxiliary switch is moved back to its first or normal position.

BENJAMIN J. WINNER. 

